首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1276767篇
  免费   99974篇
  国内免费   1986篇
耳鼻咽喉   18419篇
儿科学   44372篇
妇产科学   35013篇
基础医学   182249篇
口腔科学   33583篇
临床医学   111240篇
内科学   258054篇
皮肤病学   28019篇
神经病学   100356篇
特种医学   51204篇
外国民族医学   660篇
外科学   196468篇
综合类   27113篇
现状与发展   1篇
一般理论   377篇
预防医学   95719篇
眼科学   27872篇
药学   94876篇
  2篇
中国医学   2422篇
肿瘤学   70708篇
  2018年   13140篇
  2017年   9973篇
  2016年   10906篇
  2015年   12373篇
  2014年   17174篇
  2013年   26243篇
  2012年   36064篇
  2011年   38089篇
  2010年   22824篇
  2009年   21822篇
  2008年   36681篇
  2007年   39289篇
  2006年   39535篇
  2005年   38477篇
  2004年   37654篇
  2003年   36486篇
  2002年   35847篇
  2001年   64027篇
  2000年   66546篇
  1999年   56446篇
  1998年   15147篇
  1997年   13760篇
  1996年   14208篇
  1995年   13460篇
  1994年   12779篇
  1993年   11799篇
  1992年   44577篇
  1991年   43476篇
  1990年   42226篇
  1989年   40127篇
  1988年   36910篇
  1987年   36249篇
  1986年   33630篇
  1985年   32286篇
  1984年   24146篇
  1983年   20275篇
  1982年   11731篇
  1981年   10701篇
  1980年   9531篇
  1979年   21357篇
  1978年   14840篇
  1977年   12541篇
  1976年   11705篇
  1975年   12629篇
  1974年   14667篇
  1973年   14124篇
  1972年   12954篇
  1971年   11737篇
  1970年   11066篇
  1969年   10031篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.

Background

Arterial vascular anomalies in patients undergoing kidney transplantation (KT) are correlated with a higher incidence of early surgical complications, potentially causing graft loss. Arterial reconstruction allows patients to overcome these surgical challenges, thus minimizing the risk of poor outcomes. The aim of the present study is to retrospectively investigate the safety and effectiveness of the multiple arterial reconstruction technique with a Teflon patch in case of an unavailable aortic patch: to do so, surgical complications, graft function, and patient survival were evaluated.

Methods

During the period January 2009 to August 2016, 202 adult deceased-donor KTs were performed at our center. Group A (n = 27; reconstruction of multiple arteries) and Group B (n = 175; control group) were compared.

Results

No differences were observed between the 2 groups in terms of early postoperative course, with no vascular complication observed in Group A. No vascular patch infections were reported, nor longer cold ischemia time rates. Similarly, long-term survival rates were similar between the 2 groups.

Conclusions

The Teflon-patch arterial reconstruction technique appears to be safe and effective, with an acceptable balance of benefits and potential risks of using a prosthetic material. Studies based on larger series are needed to further validate this approach.  相似文献   
73.

Objective

Arch obstruction after the Norwood procedure is common and contributes to mortality. We determined the prevalence, associated factors, and practice variability of arch reintervention and assessed whether arch reintervention is associated with mortality.

Methods

From 2005 to 2017, 593 neonates in the Congenital Heart Surgeons' Society Critical Left Heart Obstruction cohort underwent a Norwood procedure. Median follow-up was 3.7 years. Multivariable parametric models, including a modulated renewal analysis, were performed.

Results

Of the 593 neonates, 146 (25%) underwent 218 reinterventions for arch obstruction after the Norwood procedure: catheter-based (n = 168) or surgical (n = 50) at a median age of 4.3 months (quartile 1-quartile 3, 2.6-5.7). Interdigitation of the distal aortic anastomosis was protective against arch reintervention. Development of ≥ moderate tricuspid valve regurgitation and right ventricular dysfunction at any point was associated with arch reintervention. Nonsignificant variables for arch reintervention included shunt type and preoperative aortic measurements. Surgical arch reintervention was protective against arch reintervention, but transcatheter reintervention was associated with increased reintervention. Arch reintervention was not associated with increased mortality. There was wide institutional variation in incidence of arch reintervention (range, 0-40 reinterventions per 100 years patient follow-up) and in preintervention gradient (range, 0-64 mm Hg).

Conclusions

Interdigitation of the distal aortic anastomosis during the Norwood procedure decreased the risk of arch reintervention. Surgical arch reintervention is more definitive than transcatheter. Arch reintervention after the Norwood procedure is not associated with increased mortality. Serial surveillance for arch obstruction, integrated with changes in right ventricular function and tricuspid valve regurgitation, is recommended after the Norwood procedure to improve outcomes.  相似文献   
74.
75.
76.
77.
78.
Demodex mites are microscopic arachnids found in the normal skin of many mammals. In humans, it is well established that Demodex mite density is higher in patients with the skin condition rosacea, and treatment with acaricidal agents is effective in resolving symptoms. However, pathophysiology of rosacea is complex and multifactorial. In dogs, demodicosis is a significant veterinary issue, particularly the generalized form of the disease which can be fatal if untreated. In each species, clinical and molecular studies have shown that the host’s immunological interactions with Demodex mites are an important, but not fully understood, aspect of how Demodex can live in the skin either as a harmless commensal organism or as a pathogenic agent. This review outlines the role of Demodex mites in humans and dogs, considering morphology, prevalence, symptoms, diagnosis, histology treatment and pathogenesis.  相似文献   
79.
80.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号